Pt/WO3 Nanoparticle-Dispersed Polydimethylsiloxane Membranes for Transparent and Flexible Hydrogen Gas Leakage Sensors.

Ryo Ishihara,Yuki Yamaguchi,Kenjiro Fujimoto,Yoshihiro Makino,Keishi Nishio

doi:10.3390/membranes12030291

Abstract

Hydrogen gas is a promising, clean, and highly efficient energy source. However, to use combustible H2 gas safety, high-performance and safe gas leakage sensors are required. In this study, transparent and flexible platinum-catalyst-loaded tungsten trioxide (Pt/WO3) nanoparticle-dispersed membranes were prepared as H2 gas leakage sensors. The nanoparticle-dispersed membrane with a Pt:W compositional ratio of 1:13 was transparent and exhibited a sufficient color change in response to H2 gas. The membrane containing 0.75 wt.% of Pt/WO3 nanoparticles exhibited high transparency over a wide wavelength range and the largest transmittance change in response to H2 gas among the others. The heat treatment of the particles at 573 K provided sufficient crystallinity and an accessible area for a gasochromic reaction, resulting in a rapid and sensitive response to the presence of H2 gas. The lower limit of detection of the optimized Pt/WO3 nanoparticle-dispersed membrane by naked eye was 0.4%, which was one-tenth of the minimum explosive concentration. This novel membrane was transparent as well as flexible and exhibited a clear and rapid color response to H2. Therefore, it is an ideal candidate sensor for the safe and easy detection of H2 gas leakage.

Highlights

Hydrogen gas is expected to emerge as a next-generation energy source because of its high energy density and low environmental load compared with fossil fuels [1]
Tungsten hexachloride (WCl6 ) and hydrogen hexachloroplatinate hexahydrate (H2 PtCl6 ·6H2 O) for the PtWO3 nanoparticles were purchased from Kanto Chemical Co., Inc. (Tokyo, Japan) and Kishida Chemical Co., Ltd. (Osaka, Japan), respectively
Tungsten hexachloride and hydrogen hexachloroplatinate hexahydrate were first dissolved in ethanol at predetermined atomic ratios (Pt:W = 1:13, 1:100, 1:1000) to form (Midland, MI, USA)

Summary

Introduction

Hydrogen gas is expected to emerge as a next-generation energy source because of its high energy density and low environmental load compared with fossil fuels [1]. It is a transparent and odorless gas that poses a risk of explosion when its concentration in the atmosphere is in the approximate range of 4–74 vol%. Current semiconductor-type and contact combustion-type hydrogen sensors have a disadvantage of requiring high operating temperatures and heating processes. They cannot be used when power failures occur because a power supply would be required to detect the changes in the electrical resistance of the elements. It is desirable that the sensors can be used for leakage detection in transportation pipes and storage tanks with complicated shapes

Methods

Results

Conclusion